Microsoft Word - Draft OMB Meeting Agenda-April 11 2019

OMB Meeting 4-11-2019 Pre-read Materials

201

OMAMAN-31 E: AOAC RI PTM Report 091501 ERP Use Only - March 2016

1 2 3 4 5 6 7 8 9

( Salmonella Urbana Ad 2334) and gave a positive test result at both incubation conditions. No cross-reaction was observed with the tested non-target strains. See Tables 2 and 3 for study

details and results.

Matrix Study

Each food matrix was purchased from a local grocery market, prescreened for natural contamination of the target analyte and analyzed for total aerobic count by the FDA/BAM Chapter 3 method [6]. Following the screening, each matrix was inoculated with a different strain of Salmonella spp. as indicated in Table 4, with the exception of chicken carcass rinse and chicken carcass sponge due to the fact that natural contamination was present in two separate lots. The method comparison study consisted of evaluating a total of 30 un-paired sample replicates for 13 matrixes. Within each sample set, there were 5 uninoculated samples (0 CFU/test portion), 20 low level inoculated samples (0.2-2 CFU/test portion), and 5 high level inoculated samples (2-5 CFU/test portion). For the chicken carcass rinse and chicken carcass sponge evaluation, 20 sample replicates from two separate naturally contaminated lots were evaluated. All samples analyzed by the MDA2 - Salmonella method, regardless of presumptive results, were culturally confirmed by the appropriate reference method. Each matrix that was artificially contaminated was inoculated with a different strain of Salmonella. Each inoculum was prepared by transferring a single Salmonella colony from Trypticase soy agar with 5% sheep blood (SBA) into brain heart infusion (BHI) broth and incubating the culture at 35 ± 2 o C for 24 ± 2 hours. Following incubation, the culture was diluted to a target level using BHI as the diluent. For each inoculated food matrix, bulk portions were spiked and blended in large sterile stainless steel containers. Sterile spatulas were used to mix the Prior to inoculation of cooked breaded chicken, pasteurized processed American cheese, pasteurized liquid whole egg, and creamy peanut butter, the broth culture inoculum was heat stressed for 10 ± 1 minute at 50 ± 1°C in a water bath. The of degree injury of the culture was estimated by plating an aliquot of diluted culture onto xylose lysine deoxycholate (XLD) and Tryptic Soy agar (TSA). The agars were incubated at 35 ± 1°C for 24 ± 2 hours and the colonies bulk portions to ensure the inoculum was evenly distributed.

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

100 ) AOAC Research Institute Expert Review Panel Use Only x

enumerated. The degree of injury was estimated as:

n

1(

select

−

n

nonselect

Where n select

= number of colonies on selective agar and n nonselect

= number of colonies on non-

selective agar. Using BHI broth as the diluent, the culture was diluted to a low level expected to yield fractional positive results (5-15 positive results) and a high level expected to yield all positive results. Following inoculation, a bulk lot of the matrix was homogenized by hand for 2 ±0.2 minutes and held for 48-72 hours at refrigerated temperature (2-8 °C) prior to analysis to allow time for the organism to equilibrate within the sample, with the exception of creamy peanut butter. For creamy peanut butter, following inoculation the bulk lot of the matrix was homogenized by hand or 2 ±0.2 minutes and held for 2 weeks at room temperature (24 ± 2 °C) prior to analysis to allow time for the organism to equilibrate within the matrix.

04/05/2019